I. Field of the Invention
The present invention relates generally to filtering devices and, more particularly, to filtering devices with removable filter media.
II. Description of the Prior Art
There are a number of previously known filtering devices with removable filtering media. These previously known devices typically comprise a housing which defines an interior chamber while an inlet and outlet are secured to the housing and open to the chamber. Conventionally, one end of the housing is open and the filter assembly is removably inserted through the open end of the housing and to a filtering position. In its filtering position, the filter element is positioned in between the housing inlet and outlet and, thereafter, a cover is detachably secured across and closes the open end of the housing.
A number of these previously known devices utilize a filter bag as the filter media. Such filter bags are constructed on flexible, cloth like material and are available in a number of different mesh sizes. These previously known filter bags are typically tubular and cylindrical in construction having one open end and closed at its other end. A rigid rim secured around the open end of the filter bag engages an inwardly extending flange formed in the housing in order to limit the insertion of the filter bag into the housing. These previously known filter devices which utilize filter bags as the filter media, however, suffer from a number of disadvantages.
One disadvantage of such previously known filtering devices is that it is oftentimes difficult to move or seat the filter bag in its filtering position due to the flexible material of which the filter bag is constructed. Futhermore, unless the filter bag is properly seated in its filtering position before operation of the filtering device, the filter bag may not be seated in its filtering position during the operation of the filtering device.
A still further disadvantage of the previously known filtering devices with filter bags is that the surface area of the filter bag and thus its filtering capacity, is necessarily limited by the size of the housing. If additional filtering capacity is necessary, it has been previously necessary to either increase the diameter and/or length of the housing to enable a larger filter bag to be used. Such changes, however, unduly increase the overall cost of the filtering device.
Many previously known filter devices include fluid bypass valves which permit continued fluid flow through the device despite a clogged filter condition. Previously, however, it has been necessary to house the bypass valve in a housing extension which significantly increases the cost of the housing and, thus, the cost of the filter device.